Battle for the Kingdom
by robertkellett
Summary: During his latest adventure, Sora and company stumble upon a world in grave danger. Joining the forces against evil, Sora teams up with Star Butterfly and Marco Diaz to save Mewni from an army of darkness. (Spoilers for KH3 Featured, Takes Place Before Final Battle)


_**Hello guys :). This is my answer to how much I'm enjoying KH3; so much so I'm writing a fic on it. This won't be super long, likely another six or so chapters, but want to explore a 'what if' The Kingdom of Mewni was one of the worlds featured in KH3 and how that would turn out. This idea was something I actually pondered on a while ago but never fully realized. Now is the right time for this I think, so hope you all enjoy!**_

* * *

Flying around in deep space, Sora had his hand firm on the Gummy Ship's controls. Looking over his shoulder, he spotted his best friends Donald and Goofy soundly sleeping. Donald twitching at every sharp turn Sora was making made the Keyblade wider snicker to himself. Setting the gummy ship to auto-pilot, he summoned his keyblade, having a blank expression on his face. Memories of exploring a lot of worlds recently made his hearts swell; hanging out with literal toys, seeing monsters crack jokes instead of scare and even meeting up with Herc to take on Hades for old times sake… A smile graced his face before the shine of his keyblade glared back at him. _So many need help and I'm not helping the ones that need it most._

Remembering what he just experienced back in the Caribbean, his grip on the keyblade tightened. For one of the few times in his life, Sora felt darkness dancing inside his heart. Will dying before his eyes, not even turning into a heartless or nobody, or vanishing… Just dying. And even though he came back, he frowned knowing that he couldn't be with his love. _If that happened to me and Kairi…_ Sora felt his heart shutter at the idea, shaking it off. But the danger in the other worlds was a lot more troubling this time out.

 _Innocent people keep getting hurt because of my mistakes._ Sora pondered, blue eyes glazed with frustration. Either darkness overcoming them before Sora and his friends could save them or danger he couldn't prevent happening, this latest adventure had a lot more close calls than he would have liked. _New princesses of heart…_ He remembered new faces like Elsa and Rapunzel, both facing so much, and his fist clenched. _They got someone with them, so why am I so angry?_

Part of his heart told him to knock off the pity party, another just silently told him to feel better, while a strange part of his heart told him to keep trying. Sora just put his weapon away and leaned back in his seat, trying to think what to do next. The vast space before him didn't offer any answers, just odd shapes, and a planet away. _Let's keep going, sure something will give me my answers._ Just as he started flying again, a golden portal appeared right before his ship.

"Guys!" Sora shouted, control of the ship oddly not responding. "We got some trouble!" Donald quacked unintelligible sounds of frustration while Goofy just fixed his hat, walking over to Sora. His eyes went wide and he gestured Donald to look. The duck grumbled before his eyes went wide as well. The trio saw a golden portal, inside it being a rainbow of colors. They looked at each other before Sora grew a wicked grin.

"Don't you dare…" Donald asked, with Sora punching the gas. "QAAAAK" He shouted as the heroes flew into the portal. They couldn't make out where to land but it felt as if they were flying through a ton of portals back to back. Eventually, they spotted some evil-looking trees and crashed right into them. Stumbling out of the ship, Donald cast Cura on everyone, glaring daggers at Sora. "You trashed our ship!"

Sora folded his arms, having a mock look of annoyance. "Excuse me, I wanted to see what this place was. You never know, we tend to find what we're looking for in odd worlds." Goofy nodded, with Donald just grumbling to himself. They looked around them, seeing very odd wildlife. Thug-ish looking unicorns gave the heroes an aggressive look, with even the trees and plant life apparently alive. Sora's face was just pure excitement, wondering what they can find in this world. Donald just had the tip of his staff lit with flames, keeping the odd plant life at bay.

"Gash, this world looks dangerous," Goofy commented, his grip on the shield tighter than usual. Sora took notice of what his friend said, nodding but a smile still on his face. Goofy just laughed, amused by his friend's antics.

Sora just narrowed his eyes ahead, seeing two figures fighting shadow creatures. "Our cue fellas." Sora charged ahead, with Donald and Goofy in tow. They jumped right into the action, Sora using his Kingdom Key to slash a heartless in half. Donald cast a storm of Firga blasts, with Goofy charging through some knight-looking heartless with easy. The two figures just smiled at the heroes, one in a red hoodie wearing some odd armor over it, the other in a torn up blue dress with heart marks on her cheeks. They nodded and the red hooded boy helped the girl in the air. "Mega Narwhal Blast!" She shouted, a surge of creatures blasting out of her palms. They took care of the remaining heartless, the girl landing with the grace of a skilled warrior.

"You okay Star?" The boy asked, his hood revealing a brown-haired young man with a mole. She spat out some blood, her face making a toothy smile.

"I'm doing great Marco, love me some action." She made a pose but nearly fell on her knees. Marco helped her up, Star's face showing clear signs of tiredness. Donald went up to them and cast Cura, making all their wounds gone. Her eyes went wide at the duck, hugging him with all her strength. "Oh my gosh! These are the guys you talk about all the time!"

Marco finally took notice and his eyes went wide. "How…" He just sighed, shaking his head. "You know, I _should_ expect to see my favorite cartoon characters being real. My life is one strange experience after the other." He held out his hand. "Nice to meet you Donald and Goofy." His eyes went to Sora and somewhat narrowed. "You looked ripped out of a Final Fantasy game."

"Uh…" Sora didn't know how to respond, feeling confused that in yet another world, he was a game character. _And my friends are cartoon characters? Twilight Town DID have that odd cartoon Scrouge put together. Maybe he spread that here?_ Shaking his head, he accepted the explanation and held out his hand. "Yeah, our…"

"What's your dimension like?" Marco asked, smiling and shaking his hand. "Sure it has more of those key things you just used. I'm pretty good with a sword myself but my fists are my favorite weapons." Star threw her arm around Marco's shoulder, making the boy blush.

"My little warrior here is such a cute knight." She kissed his cheek with the boy wanting to throw up his hood. "Name's Star Butterfly! My best bud here is Marco and we are fighting the darkness! Or something… I dunno, but these are some funky looking monsters."

Sora smiled, seeing a lot of Rapunzel and Flynn in the teens in front of him. "Those are heartless and I never saw this much attack. Is your home in danger?" His face went serious, with memories of Destiny Islands being engulfed in darkness playing in his mind.

"Well…" Star started pacing around. "I tried uniting Monsters and Mewmans, but that didn't go well. And this monster lady that hates Marco attacked us. We kicked her butt, but she came back and started soul-sucking our friends." She stopped pacing, her fists clenched in thick balls. Marco put a hand on her shoulder, giving a confident expression. "I know, we will get them back." He smiled at her and turned to Sora.

"After Eclipsa, Star's grandma tried defeating Meteroa, darkness suddenly surrounded the castle." He pointed to the distance, a pillar of darkness beaming like a homing beacon. Donald and Goofy nearly passed out at the sight. Sora's heart was so shaken, his other hearts expressed fear as well, sending a violent chill down Sora's spine. "We are trying to get our friends back, but they attacked us as if they were possessed or something."

A throw of an ax got the group's attention, making everyone back away. "As if on cue…" Star muttered, rushing ahead with Marco in hand. Donald, Goofy, and Sora followed, using Reflectra spells to block other weapons their way. Sora saw various people, looking worse for wear and donning mismatched clothing continuing to attack. Leading them was a short man with a half-broken crown, growing for some odd reason. "DAD! Snap out of it!"

 _Dad?_ Sora sighed, silently telling Donald and Goofy to run ahead with Star and Marco. Sora stayed behind and held out his keyblade. Closing his eyes, he summoned the keyblade he got from Rapunzel's world, flicking it to transform it into a staff. Warm light emitted from the flower-coated keyblade, shooting somewhat-harmless waves off light and magic at the possessed people. After careful sliding and dodging, Sora lept in the air and summoned a large tower, radiant beams of light escaping from it. Leaving most of the possessed people passed out, he ran after his friends, leaving a confused and semi-aware River groaning.

* * *

Sitting inside a damp cave, sounds of a monster moaning in pain got Sora's attention, blinking at the sound. "This is uh… One of the most interesting locations I've visited." He commented, earning a giggle from Star, resting on Marco's shoulder as he's soundly sleeping. Goofy and Donald were huddled together using a makeshift blanket Star conjured up for them. "You know this place?" Sora pointed toward deeper in the cave.

"Yeah! Marco and I came here a while ago. His parents wanted to see more of Mewni and we accidentally got them eaten by that guy over there." The monster huffed in annoyance before he stopped making noise. "We got them out but I never thought Marco and I would be hiding out here."

Sora folded his arms and leaned back on the wall, damp sounds of rain getting his and Star's attention. "You aren't a stranger to adventure or other worlds, are you?" Star shook her head and Sora smirked, feeling a kindred spirit within her. "Me and my pals have been fighting those heartless for a long time. One day…" Sora summoned his keyblade, looking at it with a somber expression. "I hope we can finally stop fighting and I can come home with my friends."

Star noticed the look of longing in Sora's eyes, for a split second seeing Marco in his place. "...I know that feeling." Sora looked at her in slight confusion. "Marco and I… Had some issues recently and we nearly lost each other." She absentmindedly took his hand, making the boy smile in his lucid state. "I don't ever want to let something like danger or stupidity on our ends pull us apart. Don't let those things happen to you, Sora."

He blinked at her comment, earning a smirk from Star. "It's that obvious I'm missing someone?" She nodded, making Sora thankful Donald and Goofy were sleeping so they couldn't tease him. "Kairi's one of my best friends, and a lot is riding on my shoulders…" He smiled, giving Star a thankful expression. "Thanks, for caring."

Marco groaned, sitting up from his sleeping position. "I know you like to use me as a pillow, but…" She kissed his cheek, silencing him for a hot second. "I'm not going to complain, sorry."

"Sora was just saying he has a girlfriend back home and misses her." Star blurted out, making Sora's face turn somewhat red. Donald and Goofy still remained sleeping, with Marco giving Sora a smirk.

"Don't Marco-It-Up and you're good buddy." Sora tilted his head in confusion, with Marco waving his hand as if he said nothing. _These guys are a bit odd. But I like them._ He leaned on the wall again, having a more focused expression. Marco and Star noticed the shift and mood, paying attention to whatever he would say next.

"Going to be real with you guys. While we normally follow 'the order', I don't want to with you guys this time out." He took out his keyblade and put it on his lap. "Those heartless are so strong, they might just destroy your world, I should know, they did that to mine before me and my friends saved it." Star and Marco's eyes went wide, both holding each other's hand in unsaid fear. "I'm thinking we try to save your friends before facing that Meteroa person." He rubbed his chin. "And I'm also thinking an evil witch and her bumbling sidekick might be having a role too."

"So it's like a grand Disney film, where the hero and his friends face the evil witch or jerk." Star went into a mock combat stance, with Marco rubbing his temples.

"It sounds more like something that would have happened if we let Toffee win." Marco commented, with Star saying 'totally' three times. He snickered at her before his face went somewhat serious again. "You know how to deal with this stuff Sora, so what's the plan?"

"We fight the heartless until we find your friends." Star and Marco gave blank expressions, earning silence from his allies before him. Marco felt his eye twitch while Star cracked her neck. "...That always works whenever I try to solve problems."

"That's what we were going…" Marco was about to shout, but he sighed, taking a deep breath. "You are just like her…" Star giggled at Marco's annoyance and ripped the covers off of Donald and Goofy.

"Come on sleepy heads! We gotta find my friend Kelly!" Donald and Goofy nearly went into a fighting stance, with Sora having a toothy smile. Donald glared at him before sighing, picking up his staff and walking out of the cave. Goofy fixed his shield on his back and followed, giving Sora a warm smile. Sora flicked his hand, summoning his keyblade and put it over his shoulder.

"Adventure awaits!" Star shouted, charging magic in her fists and running ahead at blazing speeds. Marco followed, shouting equally loud worriedly. Sora just smiled, pushing his fear of this world's intense darkness aside.


End file.
